JPS6256275B2 - - Google Patents

Abstract

The present invention relates to an after-dyeing treatment process for synthetic/cellulosic fibre mixed substrates which have been dyed with at least one disperse and at least one reactive dye in which after fixation, the dyed or printed substrate is reductively treated at a neutral to alkaline pH with an aqueous solution containing reducing agent, whereby non-bound disperse dyestuff is decomposed such that it does not re-build up on the substrate whilst the fixed reactive dyestuff remains substantially unaffected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for post-treatment of mixed fiber substrates consisting of dyed or printed synthetic fibers/natural cellulose fibers, in particular polyester/cellulose mixed fiber substrates.

When dyeing or printing polyester/cellulose mixed fiber substrates with mixtures of disperse dyes and reactive dyes, the terminally bound disperse dyes invariably stain the cellulose fibers and the removal of such dyes causes problems.

The present invention therefore provides a method for treating mixed fiber substrates consisting of synthetic fibers/natural cellulose fibers dyed or printed with at least one disperse dye and at least one reactive dye. After fixation, this method allows the dyed or printed substrate to be decomposed, rendered colorless, and/or re-applied to the substrate without substantially affecting the fixed reactive dye. The method includes reducing treatment with an aqueous solution containing a reducing agent, the rH value of which is selected to be between 0 and 30 so as to cause decomposition to a degree that does not occur.

It is to be understood that the term mixed fiber substrate consisting of synthetic fibers/natural cellulose fibers refers to substrates consisting of polyester and natural cellulose, cellulose 21/2 acetate and natural cellulose, and cellulose triacetate and natural cellulose. Preferably, the substrate to be treated by the method of the invention is a polyester/cotton blend substrate.

The treatment can be carried out by immersing the substrate in an aqueous bath containing a reducing agent or by printing the substrate with an aqueous solution containing a reducing agent, the former being preferred.

The rH value, which indicates the degree of reducing power of an aqueous solution, is determined by the variables of the solution, ie, redox potential, pH value, and temperature. Another variable in reducing power is processing time. Therefore, the rH value required to achieve reductive decomposition of the terminally bound disperse dye while leaving the fixed reactive dye intact can be obtained by adjusting the above parameters. The reducing power of the processing solution may also depend on the nature and concentration of the reducing agent.

Calculation of the rH value can be performed according to the following formula.

rH=Uabs/0.0992 (273.16+t℃)
+2PH where t℃ is the temperature of the solution and Uabs is Ugem
+Uref {where Ugem is the potential measured with respect to a platinum electrode, e.g. by a reference electrode, e.g. an Ag/AgC1 electrode in KC1 (3M), and Uref is the potential of the standard electrode (relative to the hydrogen electrode). )}
It is.

The potentials of some standard electrodes are known, for example, the potential for Ag/AgC1 in KC1 (3M) is
260.918 (0.683t℃). Therefore, KC1
For a system containing a platinum electrode in (3M) with an Ag/AgC1 reference electrode, the rH value is given by the following formula:

rH=Ugem+260.918-(0.683t℃)/
0.0992 (273.16+t°C)+2PH The optimum rH value will also depend on the dye used. Essentially a very low rH value between 0 and 5;
That is, redox systems with relatively high reducing power can only be used if reactive dyes with special resistance to reduction are present. For example 15~
A reducing system with a high rH value of 30 and therefore a low reducing power can be used if the disperse dyes present can be easily reduced or saponified with alkalis.

The rH value of the reducing system is preferably 1-20.
However, it has a moderate reducing power, i.e. 3-20
It is best to select dyes using systems with rH values. The most preferred rH value is 3-10.

As mentioned above, the reducing power of a system depends not only on the particular reducing agent and its concentration, but also on temperature, PH and treatment time.

Depending on the reducing agent used, the higher the temperature of the treatment bath, the higher the reducing power.
For example, the reducing power of reducing systems based on sodium formaldehyde sulfoxylate increases significantly with processing temperature, and the optimum reducing power of the system is achieved only at boiling. However, when using other reducing agents, for example in reducing systems based on sodium dithionite, the optimum reduction strength is already achieved at room temperature. The choice of reducing agent and processing temperature is important because in some cases, at high temperatures, the reduced dye can re-adhere to the fibers, causing undesirable coloration in the white areas of the print or undesirable haze in the light areas. It will depend on the type of dye present. Therefore, in some cases,
Reduction treatment allows for rapid removal of unbound dye and sizing agent while preventing the reassociation of broken dye particles and their rebuilding into the substrate. It is advantageous to carry out continuously, with stepwise increases in temperature if necessary. The temperature of the treatment bath is 10-120℃, preferably
It can be varied within the range of 30 to 100°C, more preferably 30 to 80°C. If the substrate is printed in a reducing system, it may be stored at room temperature or treated briefly (ie up to 10 minutes) with saturated steam.

Selection of the PH of the processing solution will also depend on the reducing agent used. If a reducing agent that precipitates in an alkaline medium is used, the pH should be 7 or less. However, except in the above cases, in principle the treatment can be carried out over the entire PH range as long as the fibers are not adversely affected. The treatment is suitably carried out in a neutral to strongly alkaline medium (PH 7-14). When using a strong alkali, it is easy to remove hydrolyzable disperse dyes, but it should be taken into account that it may have a negative effect on the stability of the bond between certain reactive dyes and fibers and on the properties of the polyester itself. Should. Suitable agents for adjusting the PH are sodium hydroxide, sodium carbonate, trisodium phosphate, formic acid and acetic acid.

The processing time in the reducing bath depends on the reducing system, the dyeing density and print amount, and the dye used. Generally, processing times range from 5 seconds to 1 hour. For single bath treatment, the treatment time is preferably 1 to 10 minutes, more preferably 1 to 5 minutes. For multi-bath treatments, the total treatment time generally ranges from about 5 to 40 minutes, preferably from 5 to 30 minutes, with about 20 minutes being most preferred.

Processing may be continuous or discontinuous. If the treatment is carried out in a continuous process, the reduction bath should be controlled periodically and adjusted as necessary. The reduction potential of the bath can be controlled using a redox indicator.
For rH values between 2 and 4.5, Neutral Red, which changes from red to colorless, is suitable, and for rH values between 4 and 7.5, Indanthrene Yellow G, which changes from yellow to blue, is suitable.
- Paper is suitable, and methylene blue, which changes from blue to colorless, is suitable for rH values between 13.5 and 15.5. For more information on the use of such indicators and on indicators suitable for other rH values see Melliand, 30/1949, 113.
It can be found on page .

Reducing agents for processing are, in principle, the above-mentioned
It can be any organic or inorganic compound that provides an rH value and is suitable for use in an aqueous medium.
Such reducing agents can be found in the Color Index.

Suitable reducing agents include hydrogen sulfide, sulfur dioxide, thiourea dioxide, sulfites, sulfides (e.g. sodium sulfide, ammonium sulfide), polysulfides, strongly electropositive metals, metal salts in low charge states (e.g. Fe( ), salts of Zn (), Ti () and Cr ()), organic compounds that can be oxidized (e.g. aldehydes and sugars, especially glucose),
Reducing agents used in butt dyeing or electrostatic printing processes (e.g. sodium bisulfite, formaldehyde sulfoxylates, especially sodium, calcium and zinc compounds, dithionites, especially sodium dithionite, aminomethane sulfur) ate and nitrilotri-1-ethanesulfinate, especially the sodium salt).

Preferred reducing agents are sodium or zinc formaldehyde sulfoxylate, sodium hydrogen sulfide, glucose, fructose, lactose and dextrin.

The amount of reducing agent can be varied depending on other variables that affect the rH value. Treatment bath is 0.1-10g/
1, preferably in an amount of 0.5 to 5 g/1.

It is advantageous to wash the dyed and fixed fiber substrates with water to remove unfixed dyes, fixing agents and sizing agents before and after the reduction treatment. As mentioned above, the reduction treatment can be carried out in several baths, in which case the substrate can also be subjected to intermediate water washing and washing processes.

In order to increase the cleaning effect and prevent redeposition of the reduction reaction products, it is advantageous to use from 0.5 to 2 g/l of a conventional organic cleaning agent in the reduction bath (and in the cleaning bath, if used). .

The treatment can also be carried out in the presence of water softeners and/or complex formers, such as citric acid.

The method of the invention can in principle be used to treat substrates dyed with disperse dyes as given in the color index.
These are disperse dyes of the nitro, aminoketone, ketoimine, methine, azomethine, nitrodiphenylamine, quinoline, aminonaphthocoumarin, azo and anthraquinone series. However, it should be noted that not all disperse dyes give exactly the same results.

Particularly suitable disperse dyes are azo dyes, especially monoazo dyes, which are present in the coupling component (lower grade).
Particularly suitable are azo dyes having an alkoxycarbonyl(lower)alkyl, (lower)alkylcarbonyl(lower)alkyl, or cyano(lower)alkyl-amino group. Also very suitable are anthraquinone dyes having (lower)alkoxycarbonyl(lower)alkylamino or (lower)alkylcarbonyloxy(lower)alkylamino groups.

The term "lower" as used herein means alkyl and alkoxy having 1 to 6 carbon atoms.
Preferred lower alkyl and alkoxy groups are 1 to 4
, especially 1 or 2 carbon atoms.

Representative disperse dyes that can be processed according to the method of the invention are CI Disperse Yellow 42,
CI Dapers Yellow 49, CI Dapers Yellow 126, CI Dapers Yellow 202, C.
I. Disperse thread 72, CI Disperse thread 74, CI Disperse thread 107, CI Disperse thread 202, CI Disperse thread 306, C.
I. Disperse Violet 77, CI Disperse Blue 75, CI Disperse Blue 79, CI Disperse Blue 176, CI Disperse Blue
177, CI Disperse Blue 257 and CI Disperse Blue 286.

The general conditions for the process of the invention are such that the unfixed disperse dye particles are rapidly degraded and the degradation products have a very small or practically negligible affinity for cellulose or polyester. The material has properties such that it does not rebuild on the substrate during processing. The rate of decomposition and build-up of decomposition products for a particular disperse dye can be tested by the method described below.

The increasing concentration of disperse dye is varied in a bath with a mechanical stirrer. Once the boiling point is reached, add 2 g/1 sodium formaldehyde sulfoxylate and 2 ml/l caustic soda (36° Be') and white polyester/cotton base (bath ratio 1:
40). Keep the bath at boiling for 5 minutes. The substrate is then washed with running water and dried.

As a control, a sample without reducing agent is also prepared.

Disperse dyes particularly suitable for the process of the invention do not cause staining or coloring of the white test polyester/cotton fabrics at a concentration of at least 1.5×10 ⁻⁴ mol/liter.

The reactive dye used to dye the polyester/cellulose substrate to be treated by the method of the invention can in principle be any water-soluble reactive dye containing at least one fiber-reactive group. and reactive dyes of the azo (monoazo, polyazo and metalazo), anthraquinone, formazan, triphenyldioxazine and phthalocyanine series having at least one fiber-reactive group. include. Examples of suitable dyes are vinylsulfonyl, sulfatoethylsulfonyl, sulfatoethylsulfonamide, thiosulfatoethylsulfonamide, sulfatoethylsulfonylacrylamide, methyltaurinoethylsulfonylacrylamide, α-haloacrylamide, chloro Propylamide, sulfatopropylamide, haloglacial acetamide, mono- and di-halo-
The dye has at least one reactive group selected from 1,3,5-triazinyl, trichloropyrimidinyl, monochlorodifluoropyrimidinyl, methylsulfonylchloromethylpyrimidinyl, dichloroquinoxalinyl, and dichloropyrazinyl groups. Also, reactive groups derived from halocarboxylic acids, especially chloroacetyl, β-chloropropionyl, α,β-dibromopropionyl and α,β
Dyes containing -dichloropropionyl groups are also suitable.

Particularly suitable reactive dyes have good fixation rates, very good stability, low substantivity, good retention of fixed dyes on the fibers, when processed for long periods at high temperatures in aqueous media with low rH values. The dyes are such that they give dyeings or prints which show no loss in dyeing strength or change in dyeing hue.

Special selection methods for reactive dyes are as follows.

1 Mottled standard density prints prepared with reactive dyes on cotton or cotton/polyester fabrics.
After fixation, in a rotatable bath with a bath ratio of 1:40, 2 g/
using 1 part of zinc formaldehyde sulfoxylate and 1 ml of formic acid at 40°C at PH3.
Process for 5 to 10 minutes.

2 mottled standard density prints prepared with reactive dyes on cotton or cotton/polyester fabrics.
After fixation, 2 g/
1 part of sodium formaldehyde sulfoxylate and 2 ml of caustic soda (36° Be') at 90-95°C for 5-10 minutes.

3 After fixing standard density prints prepared with reactive dyes on cotton or polyester/cotton fabrics,
In a rotatable bath with a bath ratio of 1:40, 2 ml of sodium hydrogen sulfide and 2 ml of caustic soda (36
゜Be') at 60°C for 5 to 10 minutes.

The criteria for judging prints are as described above, and the maximum allowable decrease in dye density for prints is grade 4 to 5 for gray scale (almost no change).
It is.

The process of the invention by decomposing unfixed disperse dyes and unbound reactive dyes, if any, reduces the amount of normal washing of dyeings and prints, thus saving water and energy. Also, the quality of the dyeings and prints is improved because unfixed dyes are removed and the resulting dyeings are therefore brighter and wet fastnesses are improved. In some cases, sunlight fastness is also improved. In the case of print,
Undesirable contamination of white areas or areas of light hue by dyes present in the cleaning bath can be prevented.

The following examples serve to further explain the invention. In the examples, "parts" and "%" are expressed by weight, and temperatures are expressed in degrees Celsius.

The rH value in the example is measured using a Metrohm PH meter.
Measurements were made according to standard methods using an Ingold single rod chain electrode 265-85NS containing a platinum electrode combined with a reference electrode of Ag/AgCl in E350B and KCl3M. 1ml/Sodyefide
The scale of the PH meter was calibrated for direct reading of the rH value using a standard solution consisting of B (polysulfide from Sodie, USA) and an aqueous solution containing 2 ml/ml of 36° Baume NaOH. This solution, stirred at 22° C., had a pH of 12.29 and a potential of −583 mV. An rH value of 13.2 was calculated using the calculation formula described above. Once the PH meter was calibrated in this manner, the same electrode was used to directly read the rH of the reduction baths of Examples 1-10.

Example 1 Tone on polyester/cotton (67:33) fabric
In-tone prints were prepared as follows.

36 parts CI Disperse Orange 30 (liquid, 50%) 7 parts CI Disperse Red 167 (liquid, 50%) 20 parts CI Disperse Blue 79 (liquid, 50%) 23 parts CI Reactive Orange 62 1.5 parts CI Reactive Red 119 12.5 parts CI Reactive Blue 104 450 parts CI “Manutex F” 8% (commercial sizing agent) 80 parts urea X parts water 10 parts sodium bicarbonate 10 parts reduction A total of 1000 parts of printing paste with stabilizer (eg "ReVatol S") was prepared by mixing and stirring.

The mixed fabric was printed with this printing paste using a stencil printing machine, and then dried by a conventional method,
It was treated with superheated steam at 30°C for 6 minutes to solidify it. This was further processed using a washing machine as follows.

First wash with cold water with overflow, then add 3 ml of caustic soda (36°Be') and 2 g/
The mixture was boiled with water containing 1 part of sodium formaldehyde sulfoxylate at a bath ratio of 1:40 for 4 minutes. The treatment bath had an rH value of 3.0-4.5.

It was then neutralized with acetic acid, washed with cold water, and then dried.

A bright print having a dark brown color with a pure white fabric was obtained. The print had good wet and rub fastness.

Instead of treatment at boiling, the fabric could also be treated in several baths at lower temperatures. In other words, the rH value is 16.5 to 18 with the 40° treatment, and the rH value is 16.5 to 18 with the 60° treatment.
The value is 12.5 to 13.5, and the rH value is 6.0 to 6.0 with 80° treatment.
It was set at 8.5.

Similar results were obtained using a bath ratio of 1:20 instead of 1:40.

Equally good results were obtained using 5 g/l sodium carbonate instead of 3 ml/l caustic soda. 210° instead of the 5 minute superheated steam fixation method at 175°
It was also possible to carry out a fixation treatment by dry heat at 30°C for 1 minute, with similar good results.

Similar results were obtained when the treatment bath additionally contained a water softener (depending on hardness).

Example 2 A polyester/cotton (67:33) fabric was dyed continuously tone-in-tone using disperse dyes and reactive dyes.

Using a dye mixture containing 33 parts of CI Disperse Thread 167, 56 parts of CI Reactive Thread 147, and 11 parts of CI Reactive Orange 62, one-bath, one-stage continuous dyeing was carried out with the following padding liquid composition.

40 g/1 disperse dye/reactive dye mixture 60 g/1 urea 8 g/1 sodium bicarbonate 10 g/1 common salt 20 g/1 reducing stabilizer, e.g.
AM" liquid The liquid was cold padded at a dry weight gain of 70%. The fibrous material was then thermosoled at 210° for 60 seconds and post-treated as described in Example 1.

A tone-in-tone bright red dyeing was obtained.

Example 3 The disperse dye mixture used in Example 1 was replaced by 31.5 parts of CI Disperse Blue 79, and the reactive dye mixture used in Example 1 was replaced by 36 parts of CI Disperse Blue 105. A dark blue print was obtained which had an advantageous resistance of the white unprinted areas. This print had good wet fastness. Instead of the post-treatment described in Example 1, a continuous cleaning process can also be used. For example, cold water washing in the first wash bath, treatment with 2 g/1 "Lyogen DFT" (dispersant) in the second wash bath at 40°C for 60 seconds, and treatment with 3 g/1 sodium formaldehyde in the third wash bath. treatment with sulfoxylate and 3 ml of caustic soda (36° Be') at 80°C for 3 minutes (rH value 8-10), neutralized with acetic acid in a fourth wash bath and cold water in a fifth wash bath. Wash.

Similar results can be obtained by additionally using a nonionic detergent in the third cleaning bath.

Example 4 Instead of the dye mixture used in Example 2, a continuous dyeing was carried out using 7.2 parts of CI Disperse Yellow 49, 35.7 parts of CI Disperse Yellow 42, and 57.1 parts of CI Reactive Yellow 25. To the padding bath described in Example 2 was added 50g/1 of the disperse dye/reactive dye mixture. The obtained thermosol dyeing was post-treated as follows.

Wash with cold water in the first wash bath, and wash with cold water in the second wash bath.
g/1 “Lyogen DFT” (commercial cleaning agent) bath for 1 min at 40°, and a third wash bath with 3 ml/1
of caustic soda (36° Be′), 0.1 ml of sodium dithionite and 1 g of nonionic detergent for 3 minutes (rH value of the cold treatment bath was 9.5
~11), neutralized with acetic acid in a fourth wash bath, and washed with cold water in a fifth wash bath.

Optimal fastness was obtained by pre-boiling for 1 minute with an inionic detergent in the fifth washing bath.

Example 5 A print was prepared on a polyester/cotton fabric according to the procedure described in Example 1. However, instead of the disperse dye mixture of Example 1, 15 parts of CI Disperse Blue
75 and 12 parts of CI Reactive Violet 23 was used in place of the reactive dye mixture of Example 1.

Post-processing was performed as follows. That is, washing with cold water in the first washing bath, and washing with 2 g/1 in the second and third washing baths.
zinc formaldehyde sulfoxylate and 1
ml/ of formic acid (80%) at PH 3 and temperature 40° (rH values of the second and third baths are 2.5-4.0), washed with water (with overflow) in the fourth washing bath, and washed with water (with overflow) in the fifth wash bath. Boiling soaping (using common detergents) in a sixth washing bath and water washing under overflow in a sixth washing bath.

A blue print was obtained in which the white unprinted areas were advantageously resisted.

Example 6 In addition to the possibility of reducing during the cleaning process, the process can also be carried out as follows.

A solution containing a reducing agent is applied to the fiber substrate after fixation. The dyeing is then stored in a wet, semi-dry or completely dry state at room temperature or higher, or treated with steam or other energy sources. A washing process is then carried out to remove unfixed decomposed dye particles, chemicals and dyeing aids.

Application of the solution containing the reducing agent can also be carried out with a 1000 point roller, a fully engraved flat or round stencil, a spray device or a slop padder. The amount of reducing system to be applied and the subsequent treatment method are chosen such that only unfixed dye particles are destroyed.

A polyester/cotton (67:33) blend fabric was printed and fixed as described in Example 1. Then 20g/1 carob flour derivative and 2g/1 in water
A sizing solution containing 100 g of glucose was applied with a 1000 point roller. The dry weight increase rate was 70%. The material was then dried and treated in saturated steam at 102° for 5 minutes. Finally, wash the fabric with cold water,
By a solution containing 0.5g/1 nonionic detergent
Soaped at 60° to boiling point, washed again with water, and dried. A bright dark brown print was obtained, with good fastness properties, leaving virtually pure white unprinted areas. Instead of 2 g/1 glucose, 2 g/1 sodium formaldehyde sulfoxylate and 3 ml/NaOH (30° Be') or 2 g/1 zinc formaldehyde sulfoxylate and 0.5
Similarly good results were obtained using ml/ml formic acid.

Example 7 A printing paste as described in Example 1 was used to print a polyester/cotton (67:33) fabric. except that the disperse dye mixture of Example 1 was replaced by 15 parts of CI Disperse Yellow 126, and the reactive dye mixture of Example 1 was replaced by 30 parts of CI Reactive Yellow 25.

After washing the print in cold water under overflow,
2 g/1 sodium hydrogen sulfide (NaHS) and 2
Workup was carried out using a solution containing 1 ml of caustic soda (36° Be') in a bath ratio of 1:40 at 60° for 5 minutes (rH value 12.5-13.5), then neutralized and washed with cold water.
Sodium hydrogen sulfide may be present in the sulfide-in-water mixture.

Similar results were obtained using 5 g/l sodium carbonate instead of 2 ml/l caustic soda. The rH value of this solution was 12.5-13.5. or,
5g/1 trisodium phosphate could also be used instead of sodium carbonate. In this case, the rH value is 12
It was ~13.

Similar results were obtained using various alkaline systems with practically the same rH values, with a treatment temperature of 95° instead of 60°.

Example 8 Prints were obtained as described in Example 1. However, instead of the disperse dye mixture of Example 1, 24 parts of CI Disperse Yellow 126 (liquid, 50%) and 40 parts of CI Disperse Yellow 126 (liquid, 50%) were used.
Using CI Disperse Thread 72 (liquid, 50%),
The reactive dye mixture of Example 1 was replaced with 24 parts CI Reactive Yellow 25, 1.8 parts CI Reactive Orange 64 and 6.2 parts CI Reactive Red.
147 was used.

Post-treatment was carried out as follows.

The fabric was washed in cold water and washed at a bath ratio of 1 in three baths, each containing 3 g/1 glucose, 5 g/1 sodium carbonate, 0.5 g/1 nonionic surfactant, and 1 g/1 commercially available water softener. :40 processed.

Treatment was started at 60° and the rH value was 20-22. The second bath had a temperature of 80° and an rH value of 14-16. In the third bath, treatment was carried out at 95° and the rH value was between 9 and 12.5. The fabric was then neutralized and washed under cold running water.

Similar results were obtained by substituting 2 ml/l of caustic soda (36° Be') for 5 g/1 sodium carbonate, giving virtually identical rH values.

In all baths, 3 g/1 fructose can be used instead of 3 g/1 glucose, in which case the rH value is 20-22 for the 60° bath, 14-17 for the 80° bath, and 14-17 for the 95° bath. In the bath, it was 9-11.5.

Alternatively, 3 g/1 ascorbic acid can be used instead of fructose, in which case the rH value will be 16-18 for a 60° bath, 12-14 for an 80° bath,
In the 95° bath, it was 9-13.

Instead of ascorbic acid, 3 g/1 lactose can also be used, in which case the rH value will be 20-22 in a 60° bath, 15-18 in an 80° bath, and 9-13 in a 95° bath.
It was hot.

Dextrin at 3g/1 can also be used instead of lactose, in which case the rH value will be the same in a 60° bath.
It was 20-22, 18-20 in the 80° bath, and 10-15 in the 95° bath.

Example 9 Prints were obtained as in Example 1. However, example 1
6 parts of CI Disperse Yellow 126 and 14 parts of CI Disperse Blue 176 were used instead of the disperse dye mixture of Example 1, and 8 parts of CI Reactive Yellow 25 and 8 parts of C were used instead of the reactive dye mixture of Example 1. .
I. Reactive Blue 105 was used.

The fabric was then washed with water and treated with 1 g/1 sodium formaldehyde, 1 g/1 glucose and 2
ml/ml of caustic soda (36°Be') in an aqueous solution. The treatments were carried out at 60° (rH value 13-16), 80° (rH value 7-9) and at the boiling point (rH value 5-6.5).

The same results were obtained by processing in 40° and 60° baths, further containing conventional wash, dispersant or nonionic detergents, followed by 80° baths and boiling baths.

Example 10 Using printing paste containing the following, by the usual method,
A polyester/cotton (67:33) fabric print was obtained.

28 parts CI Disperse Yellow 126 (50% liquid) 42 parts CI Disperse Thread 72 (50% liquid) 70 parts CI Disperse Blue 286 (50% liquid) 53 parts CI Reactive Black 34 7 parts CI 62 parts of Reactive Orange 500 parts of “Manutex F” 80% (commercially available glue) 50 parts of urea 10 parts of sodium carbonate 10 parts of reducing stabilizer (e.g. “Revatol S”) Add water to 1000 parts of printing material Wash with cold water, each 2g/1
of sodium formaldehyde sulfoxylate, 2 ml/ caustic soda (32°Be'), 1 g/1
water softener and 0.5g/1 washing or dispersing agent, bath ratio 1:40, 40° bath, 60° bath.
It was treated sequentially in an 80° bath and then in a 95° bath for 5 minutes. The rH value is 18-20 in a 40° bath and 12 in a 60° bath.
-16, 6-9 in the 80° bath, and 4.5-6 in the 95° bath. The fabric was then neutralized and washed under running water. A dark black print in which the unprinted areas were white was obtained. This print had good wet fastness.

The remaining amount of reducing agent in each bath was measured. A titration was performed to obtain the percentage of reducing agent used. Alternatively, potentiometric titration was performed to read the transition point between reducing power and oxidizing power.

The amount of reducing agent at the start of treatment in each bath is 100%
As a result of titration after treatment in each bath,
The amount of residual reducing agent present after treatment is
It was 99%, 98% in the 60° bath, 94% in the 80° bath, and 90% in the 95° bath.

Equally good results were obtained when processing at a liquor ratio of 1:20 to 1:100 instead of a liquor ratio of 1:40.

Claims (1)

[Claims] 1. Synthetic fibers dyed or printed using at least one type of disperse dye and at least one type of reactive dye.
When processing a mixed fiber base material made of natural cellulose fibers, after fixation, the dyed or printed base material is decomposed and rendered colorless by decomposing the terminally bound disperse dye without substantially affecting the fixed reactive dye. and/or a method comprising reducing with an aqueous solution containing a reducing agent selected to be decomposed to the extent that it does not rebuild on the substrate. 2. The method according to claim 1, wherein the base material is polyester/cotton. 3. The method according to claim 1 or 2, wherein the reduction treatment bath has an rH value of 1 to 20 as defined by the following formula. rH=Uabs/0.0992 (273.16+t℃)
+2PH where t℃ is the temperature of the solution and Uabs is Ugem
+Uref {where Ugem is the potential measured with respect to a platinum electrode, e.g. by a reference electrode, e.g. an Ag/AgC1 electrode in KC1 (3M), and Uref is the potential of the standard electrode (relative to the hydrogen electrode). )}
It is. 4. The method according to any one of claims 1 to 3, wherein the rH value is 3 to 20. 5. The method according to any one of claims 1 to 4, wherein the substrate is printed with an aqueous solution containing a reducing agent. 6. The method of claim 5, wherein the substrate is then stored at room temperature or treated with saturated steam, followed by washing and cleaning. 7. The method according to any one of claims 1 to 4, wherein the substrate is immersed in an aqueous bath containing a reducing agent. 8. The method according to any one of claims 1 to 4, wherein the substrate is immersed in a plurality of baths, each bath containing a reducing agent. 9. The method of claim 1, wherein each successive bath containing the reducing agent is at a higher temperature than the previous bath. 10. The method of any one of claims 7 to 9, wherein the substrate is then rinsed with cold water. 11. Claims 7 to 10, wherein the substrate is washed with cold water before being treated in a bath containing a reducing agent.
The method described in any one of paragraphs. 12. A method according to any one of claims 7 to 9, wherein the treatment is carried out in an alkaline medium. 13. The method of claim 12, wherein the substrate is then neutralized and then rinsed in cold water. 14. Claims 1 to 13, wherein the reducing agent is selected from the group consisting of sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate, sodium hydrogen sulfide, glucose, fructose, lactose, and dextrin. the method of. 15 Monoazo disperse dyes and (lower) alkoxycarbonyl( Claims 1 to 3 are dyed or printed with one or more disperse dyes selected from anthraquinone disperse dyes containing (lower) alkyl- or (lower) alkylcarbonyloxy (lower) alkyl-amino groups. The method according to any one of Item 14. 16 Base material is CI Disperse Yellow 42, CI
Disperse Yellow 49, CI Disperse Yellow 126, CI Disperse Yellow 202, CI Disperse Thread 72, CI Disperse Thread
74, CI Disperse Thread 107, CI Disperse Thread 202, CI Disperse Thread 306, CI
Disperse Violet 77, CI Disperse Blue 75, CI Disperse Blue 79, CI Disperse Blue 176, CI Disperse Blue
177, CI Disperse Blue 257, and CI Disperse Blue 286. .